The prior art relating to aluminum phosphate and to its production is explained in detail in U.S. Pat. No. 5,030,431. Disclosed in this patent specification is a novel production process with which homogeneous amorphous aluminum phosphate with high pore volume and relatively large pore diameters is successfully produced. The essential feature of the aluminum phosphate known from U.S. Pat. No. 5,030,431 is the combination of high pore volume of at least 1.0 cm.sup.3 /g and relatively low surface of ca. 200 to 400 m.sup.2 /g. This means that the average pore diameter is at least 12.5 and preferably at least 15.0 nm. The examples of this patent specification accordingly contain descriptions of aluminum phosphates with a pore diameter of up to 21.3 nm (Example 6).
The aluminum phosphate described in U.S. Pat. No. 5,030,431 is suitable as a cracking catalyst, as a catalyst support, especially for ethylene polymerization catalysts, flatting agent, adsorption agent and thickening agent, and, because of its aforementioned properties, leads to clear improvements in the case of these applications.
It was now surprisingly discovered that the properties of the aluminum phosphate known from U.S. Pat. No. 5,030,431 can be changed through additional process measures, so that the aluminum phosphate displays even further improved properties in relation to the aforementioned applications.